Locking means for the spring drums of clockwork mechanisms



Jan. 25 1927. 1,615,227

E. P. LEHMANN LOCKING MEANS FOR THE SPRING DRUMS OF CLOCKWORK MECHANISMSFiled Sept. 25, 1925 6 lwne/vmq Patented Jan. 25, 1927.

UNITED STATES PATENT OFFICE.

ERNST PAUL LEHMANN, OF BRANDENBUBG-ON-THE-HAVEL, GERMANY, ASSIGNOR TOTHE FIRM ERNST PAUL LEI-IMANN, PATENTWERK, OF BRANDENBURG-ON-THE- HAVEL,GERMANY.

LOCKING MEANS FOR THE SPRING DRUMS OF CLOCKWORK MECHANISMS.

Application filed September 2'5, 1925, Serial No. 58,657, and in GermanyNovember 3, 1924.

In ordinary commercial spring operated clockwork mechanisms, moreparticularly those of the simplest form for toys, the resistance forpreventing the mechanism turning in the reverse direction, when thespring is wound up, is either provided in connection with the casing ofthe clockwork or directly'in connection with the toy itself. The checkis formed either by a separate 1o spring-loaded detent or in many cases(for the sake of cheapness in the manufacture of articles by massproduction) by the body or wall of the toy itself (for instance a toymotor car). The simplest form in the latter case is the provision of aprojecting tooth punched up from the sheet metal body, be-

hind which the opposing teeth of the ratchet wheel are caused to engagethrough the laterally directed opposing pressure of the 3 spring drumand thereby to prevent the drum from running down in the oppositedirection to that of winding.

This latter simplest arrangement adopted for the sake of cheapness hasin many cases 95 the drawback, that the laterally directed check to thespring provided by the casing (for instance in the case of toy motorcars open at the bottom), is not always uniform,

in the case of articles made by mass production with cheap labour, oreasily gets bent aside subsequently in use. This drawback is completelyovercome by the present improvement, through the provision of a smallintermediate disc (the cost of which 85 is negligible) which isprevented from turning in the reverse direction by means of a projectionor pin projecting at one. side through the casing, but otherwise remainslaterally movable and thereby finds an abutment against the teeth of theratchet wheel,

which are preferably bent over laterally.

This locking disc may of course be made of any suitable material, whichwill in most cases be sheet metal, but may in certain cases be celluloidor some other thin material.

The invention is illustrated diagrammatically in Figs. 1 to 3 of theaccompanying drawing by way of example. 1 is the wall of the toy or anyother fixed surface of the toy. 2 is the shaft and 3 the hole for theshaft. 4: is the disc referred to with a tooth or tongue 5. In Fig. 1the parts 1, 4, 5 and 6 are shown somewhat spaced apart. The disc 4 issecured at 7 against rotation. 6 is the wheel to be locked.

What I claim is Locking means for the spring drums of clockworkmechanisms, comprising in combination a casing, a shaft for the springdrum, a ratchet wheel on the spring drum, a locking disc mounted on thesaid shaft and interposed between the wall of the casing and the ratchetwheel, a detent on the said locking disc capable of engaging with theteeth on the ratchet wheel, the disc with its detent being free to movelaterally, and a member projecting through the wall of the casing forsecuring the locking disc against rotating in the direction of rotationof the drum, as and for the purpose set forth.

In testimony whereof I have signed my name to this specification.

ERNST PAUL LEHMANN.

